Agitator.



WITNESSES: LVVENTOR.

WLM

` J. VAN N. BORR.

' AGITATOR.

.APPLIUATIGN FILED JULY29,1911.

2 SHEETS-SHEET l.

.Si VAN NfDoRR.

AGITATOEK. APPLIGATION FILED JULY 29', 1911. Ll. @Q Mmmm Mar. 9, 1.915.

2 SHEETS-SHEET 2.

[IVI/.ENTOR WITNESSES, l

Gly-fna una sus an ln.

afirmaron.

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Specification of Letters Patent.

rateatea nai. a, rara.

application filed ruly ae, i911. seriai No. 641,244.

T0 all lwhom t may concern.

Be it known that ll, JOHN V. N. Dorm, a citizen of the United States of America, residing at Denver, in the county of Denver and State of Golor'ado, have invented certain new and useful Improvements in .Agitators, of which the following is a specification.

My invention relates to agitators for use in the treatment of ores, and more partlcularly to apparatus of the type employed in the treatment of finely ground ores by -cyanid of potassium.y and -other solvents, to

bring the material into intimate association lwith. the cyanid solution.

The' object of the present invention resides in the provision of an apparatus of simple construction which at a compara-4 tively 'low cost of installation and operation, will effect and maintain a thorough intermixture of the ore and solvent; which in its operation provides for the proper aeration of the material under treatment; which is adjustable to vary the period of agitation for dierent sized particles of ores, and will agitate the pulp at any selected degree of density; which is automatic and continuous in its action and, in which the process of solution is materially expedited by a scouring and lwashing action upon the solid constituents of the pulp.

With the above enumerated objects 1n view, ll` provide a circular tank of any con' venient size in which an upright, hollow.

open-ended conduit is rotatably suspended'v from a superposedbearing. This conduit carries at its lower extremity two or more radial arms, each provided with a series of obliquely arranged scraper-blades.

'llhe arms which are pivotally connected with the conduit, extend in upwardly and outwardly inclined lines for the purpose of conducting the subsiding `material along the fiat bottom surface of the tank toward a central point below the lower open end of the conduit whose longitudinal axis is coincident with that of the tank.v The thickened matter thus continuously conducted toward the orifice of the conduit isdrawn upwardly there-through by the action of what is commonly known as an air lift, which causes the matter to rise by the introduction of air under compression 'into the conduit. The elevated material overflows the. upper edge of the conduit into a surroundmg hopper whence it {iows into two or more radially extending, downwardly inclined troughs or launders vwhich dlstribute it uniformly over the surface of the pulp contained in the tank, through openings in their bottoms. Slanting aprons, adjustably arranged below or above the openlngs in the troughs, are provided to regulate the size thereof for the purpose of classifying the discharge in accordance with the size of its solid particles and distributlng the pulp uniformly over the surface of the liquid. The ore is fed into the tank at one side thereof through a pipe near its upper edge, and the pulp is discharged at its opposite side through a conduit disposed substantially at the same elevation as the inlet pipe. It is obvious that if so desired, a plurality of the agitators may be arranged 1n series so that matter discharged from one is received into the next succeeding one. An adjustable device of simple construction is provided to regulate the density at which the pulp is discharged from the tank. This device consists of a vertically adjustablev baffle plate of curved section which is placed over the opening to provide an upright flue which receives the pulp at its lower end and conducts it to the discharge pipe. A shield flaring outwardly from the lower end of the bafHe plate is provided to restrain a percentage of the coarser particles of the pulp from entering the same.

lt will be readily understood that by proper adjustment of the lower end of the baille relative to the discharge opening in the tank, the pulp may be drawn from the tank at any desired level whereby the proportion of solids to liquid that is retained in the tank is effectively regulated, and when equilibrium is reached the pulp is discharged from the agitator at the same density at which it was introduced thereinto, but is agitated at a dierent density.

From the above description it will be observed that the agitator when properly adjusted, is automatic and continuous in its action and inasmuch as the heavier constituents of the pulp subside with greater rapidity than the lighter articles, it follows that the frequency ofp the circulatory movements of the various particles through the conduit and the surrounding Huid, varies in accordance to their size and weight, thus giving the coarser particles the values of which are more diicult rto recover, lmore active agitation.

The slowly revolving scraper arms not only convey the pulp to the oriice of the upright conduit, but also assist in the dissolution of the soluble constituents vby so advancing the sandy particles that they rub on-each other and so removeanyeoating of colloidal slime that may interferel With-the l penetration and diffusion of the solution.'

It is a well established fact that for the purpose of effecting lsolution in the tr'eatment of ores hereintofore referred to, the agitating action upon the material under treatment should not result in a movement of the entire mass, but rat-her cause independent movements of the solid particles through the solvent so as to bring them constantly in contact with fresh portions thereof.

The advantages of my improved agitator over other well-known methods may be readily understood.

ln vair agitation alone it is usual to have great height compared to depth, to slope the bottom into a cone and especially with a regrouud' product to use enough air to cause violent circulation in order to avoid building upon the cone, thus requiring much more power than would otherwise be necessary and using an excess of air which would consume eyanid, etc. The former' objection i. e. excessive power, applies also to screw agitators'. `With mechanical arm agitators which usually operate in the bottom of a tank, it is found that a violent agitation is required at the bottom in order to produce enough agitation at the top, and if aeration is required that must be added.

In my 4agitator which combines the good points of mechanical and air agitation, a

- slow operation of the plow arms induces a slouT motion of the wholel pulp and prevents any accumulation of thickened material on the bottom. The air lift insures the aeration of all the pulp and Vsolution as often as necessary, and its complete change of position, but allows the regulationof the power to accomplish the extraction at minimum cost with no necessity of use of additional power for mechanical reasons only. Oompared with centrifugal pump agitation there are no wearing parts and the agitation is uniform all over, while the power isa small fraction of that required. With granular material the lifting of the thick pulp and dropping it through the solution is a great saving' over circulating the whole mass and gives the maximum relative motion between solids and liquid.

The advantageous features'of my invention set forth in the vabove description, are of particular importance in the modern method of treating reground sand and slime together which, while simplifying the operation and construction of the mill, introduces both mechanical and chemical diiculties not found in the separate treatment of the sand and the slime as was practised in the earlier period of the cyanid process.

The selective feature of my invention whereby only thefthickened pulp is moved, naturally reduces the cost of operatidn, for while for example, it would require a lifting of four parts of mixture, by weight, for each'fpart of solidsina-threeto one pulp, only a .lifting of two parts ofthe mixture will be necessary to movejthe same amounts of solids in a one to one pulp.

An embodiment of `.my invention is illustrated in the .accompanyingdrawings-in the various views of which like parts are similarly designated, and which- Figure 1 represents a central, vertical scction through the apparatus, Fig. Q, a transverse section taken along the line Qf-Q, Fig. 1, Fig. 3, a similar section along the line 3-3 Fig. l, and, Fig. fl, a sectional, perspective view of a portion of one of the distributing troughs, showing the construction of the discharge openings in the bottom thereof.

The reference character 2 designates the cylindrical tank, and 3 the upright conduit which is rotatably suspended therein from a bearing 4, by means -of a 'hollow shaft 5 which extending within its upper portion, is rigidly connected therewith by means of a nui'nberof lugs 6. The shaft 5 is provided at its upper extremity with a worm wheel 7 which meshes with a worm 8 upon a shaft 9 which may beconnected with any suitable source o f power.

The radial arms 10 which `carry the series of oblique'ly arranged scraper blades 12, are pivotally attached at the lower end of the conduit 3 and they are adjustably sus pended in an upwardly and outwardly iiiclined position by means of rods 13, which at their upper ends are connected with a collar 1.4 which is vertically slidably connected with the conduit. The upper extremity of the conduit 3, which projects above the level of fluid in the tank, carries the surrounding hopper 15 which communicates' with the downwardly directed, radial distributing troughs 16. The discharge openings 17 in the` bottoms of these troughs are formed by cutting the latter along three edges of a rectangle and bending the included portion 18 up or downwardly along the fourth edge of the same. By bending the aprons thus formed, to different angles,

thel size of the material discharged through the respective openings may be readily regu-l lated to suit varying circumstances and conditions.

The material to be treated is introduced into the tank through a conduit 19 at the upper portion thereof, and the pulp is discharged therefrom by means of a conduit 20 which connects with an orifice formed substantially on a level with the inlet.

The egress orifice is covered by the baffle `21 which is vertically slidably mounted in guideways 22 upon the inner surface of the tank, and which terminates at its lower extremity in an outwardly flaring shield 23, the function of which has beenhereinbefore explained.

The air required to lift the thickened material through the hollow column 3, into the surrounding hopper, is introduced into the column through a series of small apertures formed at the lower end of a pipe 24 which extends axially through the conduit and the therewith connected shaft 5, to connect at its upper extremity with a source of air under compression.

As the operation of my apparatus has been referred to at intervals in the course of the foregoing description, it will only be necessary to describe it very briefly at this point. The material to be treated is fed through the pipe 19 into the tank 2 where it joins the pulp already contained therein, in its circulatory movement from the surface downwardly toward the orifice at the lower end of the conduit 3 and thence upwardly through the latter by the action of the air lift, to be distributed uniformly over the surface of the pulp through the openings in the troughs 16. In the above described movement, the solids which gradually settle in the tank, are conveyed toward the orifice of the conduit by the action of the Scrapers 12 on the rotating arms 10, and the sand which settles faster than the'colloidal matter is in consequence, drawn most frequently through the air-lift.

The pulp is discharged from the tank 'through the upright flue formed by the baile 21, and the therewith communicating conduit 20, and inasmuch as the density of the matter contained in the tank must necessarily vary in ratio to its depth, the density of the discharged pulp may be readily determined by varying the elevation of the lower end of the bafie, the shield 23 restraining the coarser particles contained in the pulp as hereinbefore explained.

Having thus described my invention what l claim and desire to secure by Letters- Patent is:

1. An agitator comprising a vessel, an upright conduit having an ingress-opening near the bottom thereof, and an egress opening at its opposite end, means for conveying 'matter within the conduit to its egress-opening, and a launder disposed to receive matter discharged through the latter, and provided withopenings for the distribution of said'matter over the surface of material contained in the vessel and with adjustable aprons extending obliquely relative to the said openings.

2. An agitator comprising a vessel, an upright rotary conduit having an ingress opening near the bottom thereof and an egress opening at its opposite end, outwardly extending arms at the lower end of the conduit, having obliquely arranged scraper blades, andadapted to be raised to a vertical position, means for raising matter conveyed to the ingress-opening, to the egress-opening of the conduit, means for distributing matter discharged through the latter uniformly over the surface of material contained in the vessel, according to the size of its particles, and a vertically adjustable, upright flue having at its lower end an inlet within the vessel.

3. In an agitator, a vessel having a substantially fiat bottom, means for effecting a continuous movement of matter from a point near the said bottom to a point adjacent the surface of material contained in the vessel, and mechanical means for conveying subsided matter toward the rst-mentioned point.

4. In an agitator, a trough having discharge openings, and adjustable aprons extending obliquely relative to said openings.

5. In an agitator, a trough having discharge openings and integral aprons extending obliquely beneath said openings.

,6. lin an agitator, a vessel, means for raising subsiding matter from a point near the bottom thereof, and a device for the distribution of said raised matter in said vessel, provided with openings at different distances from the center of the vessel and with means to separately vary the sizes of said openings. j

7. lin an agitator, a vessel, a rotary conduit having an ingress opening near the bottom thereof, and an egress opening atits opposite end, means for the introduction of air into said conduit, and means connected with said conduit to convey by` its rotary movement, subsided matter toward the ingress opening thereof.

8. In an agitator, a vessel, a rotary conduit having an ingress opening. near the bottom thereof, and an egress opening at its opposite end, means for the introduction of air into said conduit, means connected with said conduit to convey by its rotary movement, subsided matter toward the ingressopening thereof, and a device connected with said conduit to receive matter discharged through its egress opening and to distribute the same by its rotary movement, in the said vessel. j

9. In an agitator, a vessel having an out.- `let, and a iiue in communication with said outlet and having an inlet within the said vessel, said ue being adjustable to vary the distance of its inlet to the bottom of the vessel.

10. In an agitator, a vessel having an outlet, means for raising matter from a point near the bottom of said vessel, means for conveying subsiding matter toward said point, and adjustable means for conducting 'matter from a selected depth of said'- vessel, to the said outlet.

11. In an agitator, a trough having discharge openings, and aprons extending obliquely below the same, said aprons being bendahle to vary the distance between them and the part of the conduit in which said openings are formed- 12. In an agitator, a vessel, a rotary up.- right conduit having an ingress opening near the bottom thereof and an egress opening at its opposite end, means connected with said conduit for eifecting by its rotary motion, a flow of material adjacent said bottom,` toward said ingress opening, and means for raising matter in the conduit to the egress opening thereof.

13. In an agitator, a vessel, a rotary upright conduit having an ingress opening near'the bottom thereof and an egress opening at itsopposite end, means connected with said conduit for edecting by its rotary motion, a flow of material adjacent said bottom, toward said ingress opening, means for raising matter in the conduit to the egress openingthereof, and 'means connected with the conduit for distributing by its rotary movement, said raised matter in the said vessel.

14. In an agitator, a vessel, an upright conduit having an ingress opening near the bottom thereof and an egress opening at its opposite end, a pipe for theintroduction of air into said conduit whereby to raise loose material from the bottom of the vessel in the said conduit to the egress opening of the same, and mechanical means for preventing material subsiding toward said bottom from assuming a solid state, thereby causing the same to iow toward the said ingress opening to replace matter raised in the conduit.

15. In an agitator, a vessel, a rotary upright conduit having an ingress opening near the bottom thereof and an egress opening at its opposite end, a pipe for the introduction of air into the said conduit whereby to raise loose material from the bottom of the vesselin the conduit to the egress opening of the same, and mechanical means connected with said conduit for preventing by its rotary movement, material adjacent the bottom of the vessel from assuming a solid state, thereby causing the same to liow toward said ingress opening to replace matter raised in the conduit.

16..In an agitator, a vessel, means for raising matter from a point near the bottom thereof, and a rotary device adapted to discharge said raised matter in said vessel at different points from its aXis of rotation in accordance with the sizes of particles contained in said matter.

17. I-n an agitator, a vessel, an upright conduit having an ingress opening near the bottom thereof and an egress opening at its opposite end, means for raising loose material from the bottom of the said vessel, in the said conduit to the egress opening of the same, and mechanical means for preventing material subsiding toward said bottom from assuming a solid state, thereby causing the .same to flow toward the said ingress opening to replace matter raised in the conduit.

18. In an agitator, a vessel, means for raising subsiding matter from a point near the bottom thereof, and a rotary device having means for distributing said raised matter uniformly overthe entire surface of Inaterial contained in said vessel.

19. In an agitator, a vessel, an upright conduit rotatably suspended within said tank, with its open lower end in spaced relation to the bottom of the same, means above the tank for the rotation of said conduit, a contrivance connected at the lower end of said conduit for effecting by rotation of the latter a= flow of material toward the opening at its said end, and means for raising matter in said conduit to a point of discharge at its upper end.

20. In an agitator, a vessel, an upright conduit rotatably suspended within said tank, with its open lower end in spaced relation to the bottom of the same, means above the tank for the rotation of said conduit, a contrivance connected at the lower end of said conduit for effecting by rotation of the latter a How of material toward the opening at its said end, means for raising matter in said conduit to a point of discharge at its upper end, and means connected with the conduit for receiving matter thus discharged therefrom and distributing the same in the said vessel.

21. In an agitator, a vessel, a rotary, upright, open-ended conduit suspended therein in spaced relation to its bottom, means at theupper end of the conduit for distributing material discharged through said end, in the vessel, means connected with said conduit for edecting by its rotary motion, a

How of material adjacent said bottom to- In testimony whereof l have axed my Ward the lower end of the conduit, and a signature in presence of two witnesses. stationary airsupply pipe extending JOHN VAN NOSTRAND DRR. through the upper end of the conduit, to a Witnesses:

5 point adjacent the loweiI extrelrnity` of the G. J. RoLLANDnT,

' same. v 1

L. RHoADns.. 

